There has been some discussion of techniques to sail with a failed rudder, but I didn't see any comprehensive and simple explanations. As I just experienced a non-practice event (I think the day this thread was started), I thought I could share what I learned (and remembered eventually from basic sailing, and professional aeronautical knowledge).

I was out for a sail, and was going to meet up with a colleague (in a 14' dingy) and it was a very nice sail day, fairly sunny and steady winds 15+ knots. I was reefed to about 2/3 sail just to take it a little easy but I felt my rudder (TI, 2012 year) wasn't fully down. I retracted, but it jammed, and I used a lot of force to redeploy, but it didn't make it fully down. Now a little off course, I applied full rudder, and the pin sheared right away. Unfortunately this was pin #2, as I found the upper clevis portion sheared at the end of last year (the lines held it in place then, but before realizing the problem, it just seemed less effective).

Now for the important part. After reefing and assessing things I first started out reefed to about 1/3 and used the paddle to steer, and home was upwind. I couldn't come close to holding course. Not having too far to go to reach the shore of the island home (in the St. Lawrence just W. of Montreal), I tried just pedaling and steering (no sail), but to a similar effect. Sailing down wind was easy enough, so worst case I could land on the opposite shore and get a taxi home (no worries for the rapids 12 mi down wind). So after nearly giving up in fighting the wind, I eventually discovered almost by accident, that by opening nearly fully, the aerodynamic stability to wind would be just slightly positive, and then I could steer a straight course pointing nearly as well as with the rudder. In hindsight I realized that I should have figured out much sooner how to achieve "weather helm", but nearly full sail in strong wind w/o a rudder seemed unwise.

In a conventional boat, reefing the main sail moves the center of pressure forward, but not nearly as dramatically as our roller reefing mast. So when significantly reefed, the sail TI/AI is stable on the leeward end of the boat so it wants to go downwind (lee helm), and when full, has the opposite tendency as I previously described. I didn't try to see if I could hold a beam reach but that might make good practice another time.

I was back in the water on Monday after visiting the dealer and backing off the rudder bolt, and slightly shortening the up/down lines too. The aft position up-rudder pulley was damaged (the line jumped and jammed in the block) so we swapped with the front position until the replacement (and a spare) arrives.

P.S. The emergency rudder looks like a good and simple idea. My only concern is damaging the scupper. If this was a critical safety item (depending on where/when sailing), potting a bushing into the scupper might be a good idea. The down side is that it would reduce the OD of the shaft, so it might need to be a stronger material.

Thanks for your thoughtful comments. I totally agree that damaging a scupper is an absolute no-no. I took a painter's pole (thin-walled glassfibre) and cut a slot vertically. So when you insert it in the scupper, the glass tube compresses (due to the clearance provided by the slot) like a huge inner circlip. The springiness means that it sits firmly inside the scupper, ensuring that the dowel (25mm diameter) uses the glass tube as a bearing.It is a snap to replace the glass tube if it wears (highly unlikely as this is for emergency use after all)

What's the distance b/n the upper and lower contact point of the fiberglass sleeve?

The glass tube sticks out a bit at both top and bottom. Due to the Hobie rotomold process, scupper tubes often have a slight mismatch between top and bottom molds, so having a continuous bearing tube is the best solution I could think of to make up for any irregularity inside the scupper. The additional 2mm or so wall thickness of the glass tube is probably increasing the strength of the scupper walls, despite any loads imposed by the emergency rudder.

I made this video (I go by offshoreweekends on another site) to show an emergency hand rudder control that can be used in case any of the three rudder lines should break on a Hobie Adventure Island. The device can be built for about $1 and stores on the boat for instant access if ever needed. In the video you will notice that I am sailing with Tandum amas and am not using the aka braces. I was testing my aka safety lines that day to be sure that the lines can support the TI amas in case one of the aka brace bolt were ever to break.

There are three lines attached to the PVC handpiece. One line attached in the center of the PVC goes to the rudder down line attachment on the rudder. By keeping tension on this line you keep the rudder down. There is two lines attached, one on each side of the PVC which go to the turning lines on opposite sides of the rudder. Rotating the PVC steers the boat.

My Mkii version imvolved attacking an old plastic chair leg with a jigsaw to make "outriggers" for the rudder, to attach emergency steering lines to. One side has adjustable bungee tension, while the port side has 2 to 1 gearing to lighten steering loads. Both sides can be cleated for long trips.(The photo shows the flimsier Mki version of the outriggers, which broke when the rudder pin did).

Tony your design was actually the inspiration of what I did. The downside of mine is that the wire get tangled occasionally when I deploy it. What I like is the fact that the PVC handle is small and sits waiting out of the way for the day I really need it.

Just run the port/starboard lines around those Railblaza G-Holds (or through attached carabiners) and you'll have a decent pulley system that will take all the strain off your arms. Lean back, pull and enjoy the ride.